Get More from Curls

Abdominal strengthening exercises are useful for preventing and treating low back pain, but traditional curls can lead to underactivity in certain muscles--the transversus abdominis (TA), which supports the abdominal wall, and obliquus internus (OI), which supports internal organs--that may actually lead to or worsen back pain.

Researchers measured muscle activation during standard crunches and three variations: hollowing (pulling navel toward spine) followed by curling, bracing (laterally flaring the abdominals) prior to curling and holding, and hollowing followed by rotation. All three variations activated all muscle groups more that a traditional curl. The hollow and curl variation produced the strongest activation of the TA/OI.